1. Field of the Invention
The present invention relates to a drive device for a hybrid electric vehicle that is equipped with an internal combustion engine and an electric motor to propel a hybrid electric vehicle.
2. Description of the Related Art
A conventional drive device for a hybrid electric vehicle of this kind is disclosed in U.S. Pat. No. 6,478,705. This conventional drive device for the hybrid electric vehicle has two motors/generators (hereinafter “motor/generator” is referred to as “M/G”) and two planetary gear sets.
However, in the above known conventional drive device, there is a problem in that it cannot drive the hybrid electric vehicle by using both the motors at the same time to obtain large driving torque when it runs the hybrid electric vehicle as an electric vehicle.
It is, therefore, an object of the present invention to provide a drive device for a hybrid electric vehicle in which two M/Gs can drive at the same time to run the hybrid electric vehicle in an electric-vehicle driving mode, thereby capacities of the M/Gs being capable of being decreased.